The compact size, high reliability and optical characteristics of flat panel displays makes them well-suited for use in electronic instruments. However, flat panel displays are sensitive to mechanical stresses imposed on the displays when they are mounted in instruments and the displays require periodic servicing to replace backlighting lamps for the viewing portion of the displays.
Presently, flat panel displays are mounted onto the front frame of an electronic instrument using screws that are threaded through a series of mounting holes provided on the display assembly. The front frame requires precision machining to achieve flatness so that mechanical forces on the display are uniformly distributed when the screws are tightened. Nonuniform forces induce mechanical stresses on the display that result in visible fringing patterns on the viewing surface of the display. While the precision machined front frame accommodates the display's sensitivity to mechanical stresses, the machining process is time-consuming and increases the manufacturing cost of the electronic instrument in which the flat panel display is used.
In order to protect the viewing portion of the flat panel display and to provide electromagnetic shielding for an electronic instrument, a glass plate, or optical window, is typically positioned between the flat panel display and the front frame. Additional hardware used to secure the glass plate to the front frame makes assembling and servicing the flat panel displays time consuming.
In presently available instruments, a compressible gasket placed between the flat panel display and the glass plate forms an environmental seal that prevents dust and moisture from entering the interstitial space between the glass plate and display and obscuring the viewing portion of the display. When the flat panel display is serviced, the seal is broken and the display needs to be reinstalled in a low moisture, low particulate environment to maintain visual clarity of the interstitial space. When such an environment is not present, the instrument must be transported to a suitable servicing environment to reinstall the display, adding to the inconvenience and cost of replacing the backlighting lamps in the flat panel display.
Accordingly, there is a need for a mounting system for flat panel displays that accommodates for sensitivity of the displays to mechanical stresses and that provides for quick assembly and servicing of the flat panel displays in electronic instruments.